When the War of Power began to tip slowly but steadily in favor of the Shadow, Lews Therin proposed taking a raiding party and a circle of the most powerful Aes Sedai to the site of the Bore in order to seal it and end the threat of the Dark One breaking free of his prison. However, this plan had a number of drawbacks that even Lews Therin admitted to, and thus had a significant number of detractors.
The most prominent amongst them was Latra Decume, who supported a plan that focused on using two giant sa'angreal (the Choedan Kal) that required two ter'angreal access keys to use. The plan regarding them was to use the overwhelmingly huge amount of the One Power that could be drawn through them to annihilate the armies of the Shadow, and then to erect a barrier around Shayol Ghul until a safe way to seal the Bore could be formulated.
In order to make certain that Lews Therin did not implement his plan, she gathered every single female Aes Sedai on the side of the Light who had significant strength in the Power, and had them vow not to support Lews Therin's plan. Without women, Lews Therin would not be able to form the circle needed to safely seal the Bore, which seemed to nix his plan then and there. However, her extremely vocal opposition to Lews Therin's plan, and particularly her decision to marshal support from a strictly female cadre had the side effect of beginning a polarization of the Aes Sedai and the Hall of Servants along strictly male/female lines.
Then, problems arising from the Choedan Kal access keys being lost and the sa'angreal themselves being threatened forced Lews Therin to re-propose his original strategy, as he believed that brute force would not serve to contain the Dark One at any rate. By that point however, the polarization of the Hall had gotten so bad that even women with nowhere near enough strength to be considered for Lews Therin's raiding party had begun to side with Decume, and a number of male Aes Sedai had nearly disrupted meetings of the Hall itself. As such, Lews Therin decided to enact his plan without a circle, taking the Hundred Companions to Shayol Ghul and imperfectly patching the Bore. This however, allowed the Dark One to taint saidin, causing all male Aes Sedai to begin losing their minds and immediately driving Lews Therin and his companions mad.
Before her death during the Breaking, Latra Posae rose to a prominence which rivaled that of Lews Therin before her. During the fighting against the remaining Shadowsworn, before the Breaking put an end to what by that time seemed inconsequential by comparison, she gained the name Shadar Nor, best translated as "Cutter of the Shadow" or perhaps "Slicer of the Shadow." However, perhaps because the deeds for which she is famed occurred during an extremely volatile period in history, virtually no record was ever either made or recovered concerning her later actions, and she remained essentially unknown to subsequent generations.
It is speculated that Egwene al'Vere may be the reborn soul of Latra Posae Decume. Indeed, Egwene's role and interaction with Rand al'Thor (Lews Therin reborn) immediately prior to the Last Battle closely mirror those of Latra's prior to the Dark One's imprisonment and Breaking of the World. Egwene initially rejected Rand's proposal to break the seals on the Dark One's prison and formed a large faction of Aes Sedai and world leaders to oppose him. However, unlike her ancient predecessor, Egwene is convinced to aid in Rand's plan and the female Aes Sedai and Rand's followers are able to amass a joint assault on the forces of the Dark One which eventually leads to a decisive victory of the Light.